Is MVC one of the GoF (Gang-of-Four) patterns?

MVC is not one of the GoF patterns. They are not at the same level. MVC is what is called an architectural pattern while GoF patterns are design patterns. Basically MVC is a compound pattern (combination of more than 1 design pattern), that means it is a guide line and could be implemented using several other design patterns.

However, when implementing MVC you can take advantage of existing patterns. Take the Head First Design Patterns book they build MVC using Strategy, Composite, and Observer pattern. And I’m sure that there exists other implementations of the MVC pattern using other design patterns. I have also seen MVC being done using the Command pattern.Needless to say, even though MVC is not a GoF pattern, it is still a very useful one. GoF patterns are only a few of all existing patterns out there.